Control system



Jan. 5, 1932. 1 P. MGSHANE 1,840,122

CONTROL SYSTEM Filed Aug. 9. "1927 INVENTOR Phelan McShane ATTRNEY Patented Jan. 5, 1932 UNITED STATES PATENT oFFIcE PHELAN Mesnil/Nager PI'TTSBRGH, rENNsYLvANiA, fissisiioa To ensuite-House ELECTRIC a MANUFACTURING COMPANSLA CoR-Poiiiirion or i'EiiNsYLvANiaYV CONTROL SYSTEM My invention relates to control systems and more particularly to systems 'for operating a controller rom'a distant station.

Where apparatus is actuated by a con-v trollei, it is often times desirable to be ablek trol statio'ns and the apparatus to beoonf trolled.v A v A good example of a system in which such a requirement is of primary importance, is found in the steel industry in the operation of ingot buggies; The nature of the Work requiresa system in which it is possible to control the ingot buggy from one or more soaking pit cranes or floor stations. The coni troller and motor for driving the ingot buggy are mounted in the cab of the buggy and the electrical connections to the buggy are usually made by means of collector rails. It is readily appreciated that wheref it' is necessary to use 'collector rails, that it is eXtremely desirable to reduce the number of collector rails to a minimum. Y l v In accordance therewith, the object of my invention, generally stated, is to* provide a simple and `reliable controlsystem, and one which can be easily installed and economically maunfactured. y i 7 Y y It is also an object of my invention to pro vide, for operating a controller connected in a control system from a plurality of stations utilizing but a single conductor between the various stations and the-controller.-

Another object of my invention is to provide in a control system of r'the indicated character, for impressing` a voltage of either positive or negative pola-rityvupon the conductor leading from the controlstationg to the controller.I

A further object of Amy invention is to provide for the prevention of the simultaneous impression of voltages of both positive and negative polarity upon the single connecting conductor of a control system by different remote control stations. Y Y

Other objects of inyinvention will become apparent when the specification is read in connection with the accompanying drawing in'y which; Y

The single iguieis a schematic diagram of a control system, in which a controller is operated from a plurality of control stations, a single'conductor'being utilized to connect the control stations to the controller.` Referring now to the drawing, Ivhave il; lustrated a simple controller 1 for operating a reversible type of motor 2. In order to operate the motor in either direction, a pair of reversing contactors or switches 3 and 4 are utilized. 5-

The actuating coils 3a and 4a ofithe reversing contactors 3 and 4, as illustrated,'fare connected between the positive and lnegative line conductors 5 and 6. `They are so disposed that when both of the actuating coils 3a andV 4a are energized, the contactors remain open and the motor deenergized In order to actuate the motor, it is necessary to deenergize one or the other'of the actuating coils E3@ and 4a.

'If the reversing contactor 3 is deenergized, a circuit will be established from the positive line conductor through conductor 7, interlockB' on reversing contactor 3, conductor 8, Y vthe armature of the motor 2, conductor 9, interlock 3c on the same reversing contactor and conductor 10 to the negative line con@- ductor 6, causing the motor to operate in a predetermined direction.

To operate the motor in the other direction', the reversing contactor 4 must be deenergized, in which case a circuit will be established from the positive line conductor 5 through conductor 11, bridgemeinber 4b on the reversing contactor 4, conductor 12, the armature of motor 2, conductor 13, bridgemember 4c on the same reversing contactor 4and conductor 14 to the negative line conductor 6.

The actuating coils 3a and 4a of the reversing contactors 3 and 4, respectively, which are energized When a voltage is impressed upon the conductors '5 and 6 may bei, y deenergized by impressing a positive or neg-gv` ative voltage upon the conductor connecting the coils at a point 38, which is substantially ico the central point of the conductor. The result obtained by impressing a positive or negative voltage at the point 88 is the same as connecting one or the other of the line conductors 5 and G at that point, in which case there is no voltage across one of the coils. Consequently, one of the contact-ors will open and the polarity of the voltage applied at the point 38 will. determine the contactor that opens.

In order to impress a voltage of a predetermined polarity upon the controller at the point 88 as referred to hereinbefore, control stations 1G, 17 and 18 are provided. In the embodiment of this invention, a single conductor is employed for connecting the stations 1(5--17 aml 18 to the source of supply which, in this instance, is the positive and negative line conductors 5 and 6 and for connecting the controller l 'to the different stations. The double pole knife switches 19 are employed for establishing the desired connections between the controller and stations and in the interest of clearness in description, the similar parts of the different stations will be designated and referred to by like reference numerals.

In each controller, a plurality of magnetically operated contactors 20, 21, 22 and 23 are provided to control the different circuits. The operating coils of the contactors 2O and 21 are conn cted in series relation between the two conductors 24; and 25, which are connected to the double pole knife switch 19. Therefore, when the switch 19 is closed, the coils aj and 21a will be energized to actuate the switches 20 and 21 to their closed positions. In order to control the operation of the actuating coils 22a and 23a of the magnetic contactors 22 and 23, a manually operated switch 29 is utilized. AS illustrated, the manually operated switch 29 is connected to line conductor 24 and disposed to be actuated into engagement with two contact members and 29a` to establish a circuit through the switch 20, and the coil 22a to the line conductor 25 or through the coil 23ay and the switch 21 to the line conductor 25.

In order to impress a positive voltage upon the conductor 15 leading from the control stations 1G-17 and 18 to the point 38 on the controller, the manually operated switch 29 in one of the stations may be actuated to the reverse position into engagement with the contact member 29?). Thon the switch 29 is so actuated, the circuit as traced hereinbefore through the actuating` coil 22a will be completed to close the contactor 22, thereby impressing positive voltage from conductor 24 at the points 34 and 36, which are midway between the switches 22 and 23 and the coils 20a and 21a, respectively, as well as upon the conductor 15. The potential at the point 36 being the same as that on conductor 24,

the coil 21al of the contacter 21 will become deenergized inasmuch as there will now be no difference of potential across the coil and contacter 21 will open. In accordance with the explanation given hereinbefore relative to the reversing contactera 3 and fl, when a positive voltage is impressed at the point 38, the reversing contactor coil 3a will be deenergized sufficiently to permit contacter 8 to open, establishing an operating circuit through the motor 2 to operate it in the reverse direction.

Assuming now that it is desirable to operate the motor in the other direction, the manually operated switch 29 will be thrown to the forward position, as indicated, in which position a circuit` will be established from con.- ductor 24 through switch 29, the actuating coil 23a of the contacter 23, andthe switch 2l to conductor 25. Upon the establishment ol" this circuit, the contacter 23 will close to impress a negative voltage through the switch 23 upon the points 34, 3G and 38 in a circuit similar to t-he one traced through switch 22. The impression of negative voltage on the point 38 will permit the reversing contacter 4 to close and establish an energizing cir-- cuit to operate the motor 2 in the forward direction.

Itwill thus be seen that the controller l may be operated through a single control conductor leading from the cont-rol stations to the controller, and since the control stations are all silnilar in construction, each one may be utilized independently to effect the operation of the motor as desired. In controller 18, a number of parallel connected, manually operated control switches 29 are shown for the purpose of illustrating how a number of such switches can be utilized in one station.

In order to make it impossible to impress voltages of different polarities upon the collector rail or conductor 15 at the same time from the different control stations, it will be observed that all the points 36 located between the actuating coil of the contactors 2() and 21 of each of the control stations are energized by the saine potential. Therefore, depending upon the polarity of the voltage impressed upon conductor 15, either all the contactors 20, or all of the contactors 21. in the remote control stations will open, making it impossible to energize the actuating coils of the contactors 22 and 23, and the switches 2O and 21 heilig in circuit relation with the actuating circuit coils of the selecting contactors 22 and 28, and it is necessary that these interlocks be closed before the circuit maybe established by the actuation of a switch in another control station. Thus. a positive and convenient safety circuit for preventing the reversing contactors of the controller 1 from being operated from more than one control station at a time is provided.

ineens@ ln the operation of the control system shown in the drawings, when itis y,desired to cause ,the motor 2 to operate in a predeter, mined direction, a selected master switch in one station may be ,thrown to the vdesired di,- rection, thereby causing a `voltage .of a pref determined polarity to be impressed upon the single conductor c onnectingrthe .control stations to the controller. The motor will then be operated by means of the circuits hereinbefore traced. Further, it will be impossible to establish connections for operating the inotor in the opposite direction through the actuation of the control switches in .any of the other stat-ions, while the master controller ,on the initiating station is still in lits ,operating position.

Since certain changes may be made in the above construction, and dilierent embodiments ,of the invention may be made without departing from the spirit thereof, it is in-V tended that all matter contained in the above description, or shown inthe accompanying drawing, shall be interpreted as illustrated and not in a limiting sense.

I claim as my invention:

l. In a control system, in combination a source of direct-current, and a control station comprising a pair ot magnetic contactors having actuating coils, said actuating coils being Connected in series circuit relation with said current source, a manually operatedswitcli and a second pair of magnetic contractors responsive to said switchfor deenergizing a selected actuating coil of the irstmentioned magnetic contactors.

2. In a control system, in combination, a plurality ot cont-rol stations, a source'of direct current power for energizing the control stations, a single control-conductor disposed to be energized from either the positive or the negative line of the direct-current source of power through the operation of the control stations, said control-conductor being coniected to all the stations, and means in each control-station disposed to be energized from said control-conductor to render said stations inoperative to impress a voltage opposite in polarity on the single control conductor while it is energized in o-ne direction.

3. In a control system in combination, a main controller, a plurality of remote control stations trom which the main controller may be controlled, a source of direct-current power common to all the stations and main controller, a single control conductor connecting the stations and main controller, said inain controller being operable in response to the energization of the control conductor from one of said remote control stations, and means in each station responsive to the energization of said control conductor for rendering the idle stations inoperative thereby preventing the short-circuiting of said source of directcurrent power through said control conduc- ,tor while it is .energized to operate the main cont-roller. v

o 4. In a control system, in combination, a source of direct-current power, a plurality of control `stations disposed to be energized from the source oi power, a single control vconductor connecting the stations, means in each control station for impressing either a positive or negative voltage upon the control conductor4 from said source of direct-,current fs upon the control-conductor from said vdirectcurrent source of power, a master switch in each control station, mea-ns responsive to the operation of any one selected Ina-ster switch for Ldetermining the polarity ofthe control conductor by connecting it ,to Ione side of the power source, and means in the other control stations `operable in response to the operation of said selected master switch in one station for controlling the polarity of the. voltage that may be impressed upon the control cons ductor from said other control stations.

6. In a control system in combination, a plurality of control stations, a source of direct current power for energizing said stations, a single-control-conductor disposed to be 'energized from the power source, means in the control-stations operable to connect the control-conductor to v,either side of the power source, and normally energized means in each station disposed to become deenergized in respone tothe polarity of the v oltage impressed upon said control-conductor, to prevent theV control-conductor from being subjected to a vvoltage `of different polarity. n

7. In a control system, in combination, a

controlier, a control station for `operating the controller, a source ,of direct-current power for energizing the controller and control station, ay singlecontrol-conductor connecting the controller and control station, said control-conductor being disposed to be energized positively or negatively from said direct-current power source to operate the controller, means Aprovided in the control station for connecting" the control conductor to either side of the power source 4and. magnetically actuated means responsive lto the energization of the control conductor for rendering said connectingineans ineffective to connect the control conductor to both sides oilv the power source simultaneously.

In a control system, in combination, a controller, a control station `for operating' the controller, a source of direct-current power iior energizing the controller and control station, a single-contrel-condnctor connecting the controller and control station, said control-conductor being disposed to he energized positively or negatively from said direct-current source of power to operate the controller, inea-ns provided in the control station for connecting; the control-conductor to either side of the power source, said means con'iprisingi a, pair of `magnetic contactors and a switch for controlling' said contactors, a second pair of magnetic-contaetors disposed to cooperate in the control of said switch controlled contactors, said contactors being' responsive to the energization of the controlconductor troni one side of the power source to render one of said switch controlled contactors inoperative, thereby to irevent the simultaneous application of positive and negratiif'e voltage to the control-coiiductor.

9. In a control system in combination, a controller, a plurality of control-stations for operating the controller, a source of directcurrent power, a single-control-conductor connecting the stations to the controller, nieans in each control station for energizing the control-conductor either from the positive or the negative side of said source of direct-current power, and means responsive to the polarity et' the energized control-conductor when one station is in operation for rendering all the other stations inoperative.

l0. In a control system, in combination, a plurality of control stations, a single control conductor for connecting;` said control stations, a source of direct-current power for energizing' all the stations, means for coi'inectingr either the positive or the negative line of the direct-current power source to the single conductor troni any one of the control stations, and ineens responsive to the energization of the control conductor from any one station for locking-out all the other stations.

1l. In a control system, in combination, a plurality oi control stations, a single control conductor connectingr said control stations, a source of. direct-current power for energizing;r all the stations, the control stations coinprisinpT n'ieans for connecting either the positive er the negative line of the direct-current power source to the single control conductor, and means responsive to the energization of said control conductor for automatically preventingT the connection of both t-he positive and the negative side of the single control conductor simultaneously.

l2. In a control system, in combination, L, controller and a plurality of control stations for operating the controller, a source of direct-current power, a single control conductor for connecting each control station to the controller, means disposed in each station for energizing the control conductor either from the positive or the negative line of: the directcurrent source of power for effectingr the operation of the controller, and means responsive to the polarity of the control conductor for automatically dropping-out the other stations.

13. In a control system, in combination, a translatingr device, a plurality oi control stations provided with a plurality o'l" control switches disposed in paired relation. for causing operation of the translating` device, a source of direct-current power for the control switches and translating device and nieans responsive to the operation of a selected set of control switches of one control station to prevent operation of a non-correspendingr set of control switches in other control stations.

In testimony whereof I have hereunto suhseribed niy naine this 3rd day of August,

PHELAN MCSHANE. 

